Tina Rogers, 42, was arrested last Friday after authorities issued a search warrant for her home in the 4100 block of North Ventura Avenue in the unincorporated county area north of Ventura.
Investigators said over the past few weeks they have been receiving tips about criminal activity surrounding the home.
According to detectives, Rogers was selling drugs from her residence. They found approximately 2 grams of heroin, syringes filled with heroin, and about 1.5 grams of methamphetamine.
Along with felony child endangerment, Rogers was booked for possession of heroin and methamphetamine for sale and for being under the influence of a controlled substance.
Another person at the home, 23-year-old Anthony Maxwell, was arrested for being under the influence of a controlled substance. The 9-year-old boy was released to the Ventura County Child & Family Services.